Microsaccade

Microsaccade

Microsaccades are a kind of fixational eye movement. They are small, jerk-like, involuntary eye movements, similar to miniature versions of voluntary saccades. They typically occur during prolonged visual fixation (of at least several seconds), not only in humans, but also in animals with foveal vision (primates, cats, etc.). Microsaccade amplitudes vary from 2 to 120 arcminutes. The first empirical evidence for their existence was provided by Robert Darwin, the father of Charles Darwin.[1][2]

Contents

Function

The role of microsaccades in visual perception has been a highly debated topic which is still largely unresolved. It has been proposed that microsaccades correct displacements in eye position produced by drifts, although non-corrective microsaccades also occur. Microsaccades were also believed to prevent the retinal image from fading, but they do not occur often enough for that purpose, considering that perfectly stabilized images can disappear from perception in a few seconds or less. The current consensus is that all fixational eye movements are important for the maintenance of visibility.

Experiments in neurophysiology from different laboratories showed that fixational eye movements, particularly microsaccades, strongly modulate the activity of neurons in the visual areas of the macaque brain. In the lateral geniculate nucleus (LGN) and the primary visual cortex (V1), microsaccades can move a stationary stimulus in and out of a neuron's receptive field, thereby producing transient neural responses. Microsaccades might account for much of the response variability of neurons in visual area V1 of the awake monkey.

Current research in visual neuroscience and psychophysics is investigating how microsaccades relate to fixation correction, control of binocular fixation disparity and attentional shifts. Recent research has found a direct correlation between illusory motion and microsaccades.[3][4][5]

See also

References

Notes

  1. ^ Darwin, R. W.; Darwin, E. (1786). "New Experiments on the Ocular Spectra of Light and Colours". Philosophical Transactions of the Royal Society of London 76: 313. doi:10.1098/rstl.1786.0016. JSTOR 106628. 
  2. ^ Rolfs, Martin (2009). "Microsaccades: Small steps on a long way". Vision Research 49 (20): 2415–41. doi:10.1016/j.visres.2009.08.010. PMID 19683016. 
  3. ^ "Optical illusions: caused by eye or brain?"
  4. ^ 200-year-old Scientific Debate Involving Visual Illusions
  5. ^ The truth behind 'Where's Waldo?'

Bibliography

  • R. H. S. Carpenter. Movements of the Eyes (Pion, London, 1988).
  • Martinez-Conde, Susana; MacKnik, Stephen L.; Hubel, David H. (2004). "The role of fixational eye movements in visual perception". Nature Reviews Neuroscience 5 (3): 229–40. doi:10.1038/nrn1348. PMID 14976522. 

Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • microsaccade — noun A small, jerky eye movement that is a part of normal vision when fixating on an image, which seems to play a role in visual perception. See Also: saccade …   Wiktionary

  • Fixational eye movement — Fixational eye movements (also known as fixational instability, retinal jitter) are small, involuntary eye movements that occur during visual fixation. There are three categories of fixational eye movements: microsaccades, ocular drifts, and… …   Wikipedia

  • Saccade — A saccade is a fast movement of an eye, head or other part of an animal s body or device. It can also be a fast shift in frequency of an emitted signal or other quick change. However, this article deals with saccadic eye motion. Eye saccades are… …   Wikipedia

  • Afterimage — For other uses, see Afterimage (disambiguation). If the viewer stares at this image for 20 60 seconds and stares at a white object a negative afterimage will appear (in this case being cyan on magenta). This can also be achieved by the viewer… …   Wikipedia

  • Human eye — Infobox Anatomy Name = Eye Caption = Schematic diagram of the human eye. The human eye is similar to most mammalian eyes.Dynamic rangeThe retina has a static contrast ratio of around 100:1 (about 6 1/2 stops). As soon as the eye moves (saccades)… …   Wikipedia

  • Eye movement (sensory) — For other uses, see Eye movement (disambiguation). Eye movement is the voluntary or involuntary movement of the eyes, helping in acquiring, fixating and tracking visual stimuli. It may also compensate for a body movement, such as when moving the… …   Wikipedia

  • Eye movement — may refer to: * Eye movement (sensory), the voluntary or involuntary movement of the eyes * Eye movement in reading, the method in which eye movement assimilates written language * Eye movement in music reading, the method in which eye movement… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”